Multi-positional articulating ergonomic device with modular features

ABSTRACT

The invention is a monitor arm assembly including a rotation limiter that includes movable tabs to set the rotation limits of the arms with respect to each other or other assemblies. The rotation limiter may include exterior ring activators and outer visual references for the set limitations. The monitor arm assembly also includes a plurality of slide tracks to allow the monitor attached the arm to take a plurality of lateral positions. The assembly may further include a connector to join adjacent slide tracks.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to ergonomic office products, morespecifically to desktop and tabletop ergonomic assistance devices suchas footrests, monitor and laptop risers, writing surfaces, andarticulating supports.

Background Art

Ergonomic devices are well known in the current marketplace and areutilized in most offices today to ensure the worker and the equipmentthe working is interacting with is positioned in a way as to make theirdaily tasks less strenuous to the muscular skeletal structure of theworker. These types of products typically include numerous and variouspoints of adjustments to ensure they address certain anthropomorphic andbiomechanical understandings or standards so as to be deemed anergonomic device.

An example of such an ergonomic device is a footrest to be used by aseated office worker. A footrest, when properly adjusted allows for amore comfortable position for the user. Typically, a footrest is usedunder a desk and comes into use when the user is in the seated position.The footrest may include a platform component in which the feet of theuser engages with and may also include an underlying mechanism givingthe platform its ability to adjust in height and/or its angle position.Such a device as illustrated in FIGS. 2 and 3 of U.S. Pat. No.4,547,767, is an example of this type of prior art, and shown in FIG. 1of this application.

FIGS. 1A and 1B are a prior art patent figure illustration of anexemplary adjustable footrest from U.S. Pat. No. 4,549,767. The upperillustration labeled FIG. 1A, upper platform 38 is in the middleposition with element 58 resting on middle step element 28. Thisadjustable footrest exemplifies typical footrests whereas the upperplatform adjusts in height and angle.

As workplaces move towards an active workforce model where the worker isencouraged to work while standing or sitting, and to take active breaksto encouraging movement, adds additional need and complexity to thecategory of ergonomic footrests.

FIGS. 1 a and 1 b of U.S. Pat. No. 9,961,990 shown in this applicationas FIGS. 2A and 2B, illustrates a prior art example of a device whichprovides a footrest when a user is in the standing position whileworking, and then can be moved away by the operator when the heightadjustable table is lowered into the sitting position.

The prior art shown in FIGS. 2A and 2B is an illustration of anexemplary adjustable footrest as part of a sit stand desk from U.S. Pat.No. 9,961,990. FIG. 2A illustrates footrest element 42 in the retractedposition. FIG. 2B shows footrest element 42 in the active position alongwith the sit stand surface element 50 in the raised position.*interpretation of prior art exemplary figure

FIG. 1 of U.S. Pat. No. 6,955,400 shown here as FIG. 3 illustrates anexample of a prior art footrest with dynamic movement feature whichtransmits a sequentially actuated motorized movement to the feet andlegs of the user in its attempt to alleviate the effects of beingsedentary in an office setting.

FIG. 3 is a prior art patent figure illustration of an exemplaryunder-desk footrest with motorized movement from U.S. Pat. No.6,955,400. FIG. 1 illustrates footrest element 1, motor element 5 whichmoves to articulate armature element 10. Armature element 10 movesfootrest element 2 about pivot axis 4. Linkage element 7 allows foralternating articulation of footrest element 3.

Ergonomic writing surfaces are also known to be used to encourage properwriting and working surface angles and have adjustment and features toensure the desired position and/or angle of the upper surface is in theproper position, in height, laterally, and distance from the user.Typically, a writing surface is used to relieve stress developed fromleaning over a flat surface when writing or engaged in a similaractivity. The construct of an ergonomic or adjustable writing surfaceincludes a writing surface or platform component and an underlyingmechanism giving the platform its ability to adjust in height,laterally, fore and aft, and/or its angle position. A prior art writingsurface with some adjustability is disclosed in FIG. 8 of US PatentApplication 2004/0256535, included in the present application as FIG. 4, and illustrates the some of the noted features.

FIG. 4 is a prior art patent application figure illustration of anexemplary adjustable writing surface from US Patent Application2004/0256535 A1. FIG. 8 illustrates writing surface element 400 in itsraised position as it is positioned to rest on support element 436.

Laptop stands represent another type of an ergonomic device. These typesof devices allow the screen of a laptop to be presented higher so thereis less strain due to the reduction of having to tilt one's head forwardto view the laptop screen. FIG. 9 of U.S. Pat. No. 7,487,940, shown inthis application as FIG. 5 , is an illustration of such a device whichis designed to allow a laptop computer to be positioned as toaccommodate the ergonomically recommended upright viewing angle.

FIG. 5 is a prior art patent figure illustration of an exemplary laptopcomputer stand from U.S. Pat. No. 7,487,940. Laptop computer retainingelement 10 holds laptop computer 20 on upper element 79. Height or angleadjustments are possible through paddle element 47.

SUMMARY OF THE INVENTION

Disclosed herein is a Multi-Positional Articulating Ergonomic Devicewith Modular Features. The disclosed invention not only overcomes manyof the limitations of the prior art, it endeavors to add additionalefficiencies for the end user and the manufacturer by using a systemsapproach. This systems approach allows for core mechanisms to be sharedand to interchangeably assembled to create a multitude of ergonomicdevices. These devices use similarly design components yet aredifferentiating enough as to accommodate user variabilities as toqualify as an ergonomic device within the channel or category in whichthe unit has been modularly configured to sell through.

Due to the numerous and harmful sedentary type office jobs, the need forergonomically designed devices to counteract these effects has becomemore prevalent and the market needs have increased. In particular, sitstand devices allowing the worker to raise and lower their primary worksurface as to go from sitting to standing. This action is taken intoconsideration with our disclosed invention in the form of a footrestassembly that has a larger range of motion, is easily adjustable, andincludes an activated standing mode while easily returning to sittingmode as to accommodate both sitting and standing positions. Furthermore,the disclosed invention in the footrest assembly has taken intoconsideration in a unique and inventive manner, the newest trends ofactive movement which encourages movement even when the user is in thesitting position. With the footrest assembly, active or dynamic movementis encouraged by the core supportive arm mechanism's ability to flexdownward when additional pressure is applied beyond the user adjustableneutral setting to accommodate the flexing of the legs and articulationat the ankle joint. These actions are encouraged since the unit's useradjustable settings are not disturbed and the unit will easily return tothe user desired preset position each time after the dynamic movementhas concluded.

By interchanging the disclosed invention's top platform with another,for example from a footrest platform to a writing surface, the discloseddevice can now function in a manner desirable of ergonomic writingsurfaces with additional and unique benefits.

Typical writing surfaces have only an angle adjustment and cannot beeasily moved out of the way. The disclosed device when configured as awriting surface, the writing surface's angular orientation can beadjusted not just front to back, but angularly due to its ability topivot and rotate accommodating both right and left-hand/orientations.This additional flexibility allows the surface to sit at a more naturalposition making it ergonomically superior to standard writing surfaces.Furthermore, the writing surface configuration has the added advantageof being easily moved out of the way when the user is using a keyboardor needing access to the space underneath the writing surface.

Once again, by interchanging the disclosed invention's top platform withanother, for example from a writing surface to a laptop and/or monitorriser, the disclosed device can be reconfigured into a monitor or laptopriser. Typical laptop and/or monitor risers have a top platform, orsurface which can be adjustably raised, or lowered as to be positionedoptimally for viewing the screen. When and if desired, the top platformor surface, on the disclosed device can be raised or lowered,additionally angled forward, or backwards, and pivoted right and left.These additional adjustments allow the user to change viewing angles tomatch their working position more readily. As well, the feature allowsthe user to share their monitor or laptop screen with others by rotatingthe top platform or surface for optimal viewing.

The disclosed invention's main components include, but are not limitedto, a base for resting on a surface such as a desk top, a liftingarmature mechanism which can be in the form of a parallel or four barconfiguration, an optional upper and lower pivoting, and/or rotatingassemblies, and an optionally interchangeable top surface/s such as afoot platform, writing surface, monitor support assembly, or laptopsupport surface, and the unit's support base element/s.

Configurations of the invention may utilize a weighted base to improvethe stability of the unit throughout its entire movement range, but incertain configurations when additional stability is required, a securingclamp in addition to, or as an alternative to, the weighted base can beutilized. The base assembly optionally includes within the sub-assembly,a pivoting and/or rotating assembly which is configured add additionalmovement by utilizing a pivot and/or rotating component which interactswith a bearing surface/s and can incorporate adjustments as to limit themovement range and the force needed to initiate the movement.Additionally, if a return to center feature is desired, this can beimplemented by the addition of a biased spring arrangement. The pivotand/or rotating mechanism's force adjustment feature can be factory setusing set screws, operator modified by utilizing knurled knobs, and/orrelocated to another more accessible location by the use of a cable andactuator assembly.

The aforementioned lift assembly arm can be in the form of a parallel orfour bar arm type mechanism, if its desirous to have a support arm, inwhich the upper attached mount or platform stays relative to its userset or default factory set angle when in the raised, lowered, orpositions therebetween; otherwise a dual hinged armature with upper andlower rotational and/or pivoting assemblies would suffice in many of thementioned configurations, and is typically lower in cost and complexity.

When lift assist is desired, the arm assembly can utilize a positioningassist mechanism in the form of a torsion, extension, or compressionspring, or through the use of an expanding gas cylinder, or any othersimilar or combination of arrangements to impart the force needed forproper assistance when moving the armature throughout its desired rangeof motion. This assist feature when utilized, can incorporate anadjustment or use a multitude of assists of similar, or varied typeswhich are utilized and actuated in a manner as to ensure the amount ofassist force exerted on the armature can be set to a desired level; thisis due to the varied needs to ensure the feature meets the user'sexpectations in each of the varied configurations. The aforementionedmanual assist methods can be replaced by a linier actuation motorassembly if a motorized powered version is desired. In addition, thelift arm assembly can be supplemented by the use of a secondary, and/ormultiple force assists to aid the primary assist's functional range asto ensure when lifting and lowering the upper mount or platform, theoperator is the desired amount of force, whether variable or constant,throughout the range of the armature's movement.

The upper portion of the lift arm assembly is coupled by way of anoptional pivoting, and/or rotating assembly which could mirror theconstruction and feature set of the previously described lower pivotingassembly. Furthermore, either the upper or lower assembly, or both canincorporate a leveling gimble assembly to compensate for anymanufacturing, assembly or mounting surface irregularities, can befactory set using set screws, and/or operator modified utilizing knurledknobs. The leveling feature allows the upper mounting plate to stay atits relative set angle position throughout the armature's travel. Boththe upper and lower optionally pivoting and/or rotating assemblies mayhave a force adjustment feature which allow for separately operable andadjustable force settings which when utilized, can regulate thesequential movement of the upper mounting bracket's orientation to theunit's lower base mount assembly.

In some configurations and embodiments, it will be advantageous to makethe pivoting, rotational movement assemblies operate unambiguouslyand/or sequentially. Each of the movement assemblies can be adjusted andset to initiate its motion with a varied force from the other/s, as toeliminate ambiguity, especially in a multi-pivotal and/ormulti-rotational configuration. To ensure the primarily desired movementinitiates when the optimal amount of force is exerted in the primarymovement's actuation direction, the desired resistant setting can beaccomplished by adjusting the tensioning assembly on the pivot androtational retainer collet. By tightening or loosening the tensionmechanism, the force needed to rotate or pivot a particular jointassembly, can be tuned by adjustment as to varying the force needed tomove the that particular assembly as compared to other assemblies as tomake that one pivot/rotational assembly move with lessor or greaterforce than the another/s.

As an alternative or supplemental feature, an actuation pin, cam, orgear can be added to the pivoting and/or rotating assemblies to adjustthe resistance and/or to lock the assemblies. If controlled as a group,the actuated member would be actuated as to interlock the assembliestogether, or in the inverse, when the locking pin has not been actuated,the pivoting and/or rotating assemblies would continue to actindependent of one another. This actuation of locking and unlocking orof engaging or disengaging a resistive force, would depend on themovement control desired for the product to function as intended in thefinal assembled configuration. This optional adjustment actuation/s canbe accomplished remotely away from the actuation pin, cam or gear, byway of a cable and an actuation lever assembly.

The actuator if utilized, should be advantageously located as to allowthe operator to actuate a gas or spring lift assist mechanism. Theactuator can be remotely located and activated by way of a lever on oneend pulling a cable through the assembly activating the assistmechanism. If using a gas spring, the type that automatically locks inplace when the actuator is returned to the non-actuated position isadvantageous when a user may want a lock and unlock type positioningdevice. This allows the working surface platform to be actuated, movedand stopped and be locked in place anywhere within its range ofmovement. In certain embodiments, it might be advantageous for thearmature to not be locked in place as to be in the optimal position whenweight is applied (such as in a footrest configuration); this is so whenadditional force or weight is applied, the upper assembly actively movesand returns as to flex with the user when they are moving, leaning upon,or stretching against the device. In other embodiments of the actuationdevice, it might be used to unlock and lock a feature such as a rotationfeature as to allow the upper platform and/or the lower arm assembly topivot. Several levers and actuators (more or less) can be usedthroughout the configuration as to ensure optimal adjustment and featureactuations.

Additionally, the aforementioned rotational and pivotal assemblies, canincorporate an adjustable travel limiter to allow only a portion of itsfull range of movement to be accessible. The limiter can be preset withsome or all of its range of motion being user adjustable. The limitersettings will be determined by the final assembly and which movementswould be desirous to limit for a given situation. The adjustment can becreated by interchangeable stepped spacers which be engaged separately,as in one at a time or, can be a continuous collet with a protrusiondetail which blocks some of the pivotal or rotational range of movement.These limiter assemblies can uniquely incorporate a torsion spring whichwould assist in the rotation and/or pivotal movements. The torsionspring act as to return the pivot or rotation assembly to the initialdefault or user chosen position, whereas the pivoted or rotated assemblywould naturally return to the spring force center when the operator hasreleased the rotated or pivoted component off the default, or userchosen position—the home position. This back to center feature's homeposition can be adjusted by rotating the spring pivot assembly to set anewly desired default or home position.

In some applications, the limiter assembly may include activators to setpins to determine the range of movement. The activators may be movablerings coaxially located about the limiter assembly. With judiciousdesign, the limiter assembly may act as a rotational bearing and beconstructed as a cassette which may be replaced or substituted with anon-limiter bearing if a user so desires.

In certain uses, it is advantageous to incorporate an over-drive orclutch mechanism to protect the unit from unintended use. The disclosedinvention in the described embodiment includes at least one pivotallyand/or rotationally hinged components. The upper and lower assemblieswhich are attached by way of a pivotally hinged assembly and mountingbracket can incorporate the over-drive mechanism in the lift assisted ornon-assisted embodiment, the four-bar parallel arm configuration, or thesimpler non-four bar, dual hinged arm configuration. To move the upperassembly up and down without a lift assist, the user would manuallyposition the upper assembly to the desired position and tighten thehinged arm assembly in place. The hinged arm assembly could includedetents built into the hinge assembly as to let the user know the armhas been set to a certain position, and each of these detents could bedesigned in a way as to hold the armature in place (once the user hastightened the hinged and/or pivot mechanism) for normal use, but in theapplication of high amounts of force or weight, the detents would thenwork as a clutch and release to the next detent and so on, in such amanner as not to damage the unit's functionality. When incorporating theclutch mechanism within an embodiment which incorporates a four-barmechanism with a lift assist, the clutch mechanism will take intoconsideration the application of force or weight above the recommendedspecified limit; when this force limit is reached, the lift assist willgive way as to allow movement of the armature as to not damage theunit's functionality.

The disclosed invention has distinct unique features such as dynamicmovement, adjustability, flexibility, and modularity and are the keycharacteristics of the core mechanism which support an optionallyinterchangeable and varied top surfaces, which when assemble upon theoptionally varied number of support bases, create varied and unique userexperiences. Along with these demonstrable functional advantages, we aredisclosing a method and system in which, a manufacturer, and/ordistributor, and/or consumer can construct a multitude of ergonomicallybased products effectively and at lower cost than if they were to,design, engineer, tool, manufacture, assembled and ship each of thevaried constructs individually. The manufacturer and distributor canmass ship the components and/or construct the desired product as orderedby the consumer to save shipping, warehousing cost while responding tothe consumer's needs in a build to order premium service at much lowercosts and investment.

As of note, these disclosed configurations and embodiments are by nomeans an exhaustive list of the multitude of configurations andvariations producible by the disclosed application but is meant to beillustrative to demonstrate the advantageous ergonomic flexibility ofthe disclosed invention and its sub-components and sub features.

The listed products features and inventive embodiments as described inthis application should not be considered as limiting in any way. Thedisclosed features and inventive embodiments of this application can beapplied to a range of products which are Multi-Positional ArticulatingErgonomic Devices.

In one form, the invention is directed to a support device forselectively elevating a platform above a working surface. The deviceincludes: a base for resting on a work surface; an articulating armatureassembly; and a platform assembly. The base is coupled to thearticulating armature assembly. The articulating armature assembly iscoupled to the platform assembly. The articulating armature assembly hasa range of elevation to selectively raise and lower the platformassembly above the working surface. The elevation is selected by theuser through an articulation actuator that includes a spring.

In one form, the articulation actuator includes an actuation lever toselectively engage the spring.

In one form, the spring provides a counterforce to a downward force onthe platform assembly when the articulating armature assembly is in anupper range of elevation.

In one form, the device further includes a second spring with a forcehigher than the first spring.

In one form, the first spring provides force to the articulatingarmature assembly in a first range of elevation. The second springprovides force to the articulating armature assembly in a second rangeof elevation.

In one form, a first actuation lever selectively engages the firstspring. A second lever selectively engages the second spring.

In one form, the device further includes a range controller. The rangecontroller defines the range in which the articulating armature assemblymoves.

In one form, the spring provides counterforce to a downward force on theplatform assembly, when the armature assembly moves within the rangedefined by the range controller.

In one form, the invention is directed to a support device for elevatinga platform above a work surface. The device includes: a base; anarticulating armature assembly; and a platform assembly. The base iscoupled to the articulating armature assembly. The articulating armatureassembly is coupled to the platform assembly. The articulating armatureassembly has a range of elevation above the base. A spring is engagedwith the articulating armature assembly to provide a counterforce to adownward force on the platform assembly.

In one form, the spring engages with a range controller to limit therange of elevation.

In one form, the counterforce supplied by the spring is selectivelyengaged by an actuation lever.

In one form, the device further includes a slide plate on the bottom ofthe base. The slide plate is selectively in contact with a surface uponwhich the base rests when the base is tilted by the user. The slideplate is not in contact with the surface when the base is not tilted.

In one form, the device further includes a second spring to provide acounterforce to a downward force on the platform assembly. The secondspring applies its downward force when the articulating armatureassembly is in a second range of elevation above the base.

In one form, the second range of elevation is limited by a second rangecontroller.

In one form, the device includes a rotational bearing that allows thearticulating armature assembly to rotate with respect to the base.

In one form, the articulating armature assembly is a four bar assembly.

In one form, the invention is directed to a support device for elevatinga platform above a working surface. The device includes: a base assemblyfor resting on the working surface; an articulating armature assemblycoupled to the base assembly; and a platform assembly coupled to thearticulating armature assembly. The articulating armature assembly has arange of elevation positions. A biasing member is engaged with thearticulating armature assembly. The biasing member provides acounterforce against a downward force on the platform assembly when thearticulating armature assembly is at an elevation higher than a lowerelevation position. A range controller is engaged with the biasingmember to limit the range of elevation positions in which the biasingmember applies the counterforce.

In one form, the rotation limiter further includes a plurality of limittab guides in the outer rotational element. The limit tabs areselectively movable within the limit tab guides.

In one form, the monitor arm further includes at least one limiteractivator to selectively activate or deactivate the limit tabs.

In one form, the limiter activator is a ring positioned about at least aportion of the outer rotational element. The ring includes a protrusionto selectively move limit tabs as the ring is rotated.

In one form, further including a second ring positioned about at least aportion of the outer rotational element, the ring including a secondring protrusion to selectively mover limit tabs at the second ring isrotated.

In one form, the inner rotational element, the outer rotational element,and the ring are coaxially aligned.

In one form, the limit tabs are cylindrical pins having a major axisparallel to the coaxial alignment.

In one form, the limit tab guides are apertures in the outer rotationalelement. The apertures are sized smaller than the diameter of thecylindrical pins.

In one form, the number of limit tabs is at least one less than thenumber of limit tab guides.

In one form, the base is a second arm.

In one form, the monitor arm further includes a connection plate coupledto a second end of the arm. The connection plate is in slidingengagement with a first slide track. The connection plate has perimeteredges. The first slide track includes perimeter channels. The perimeterchannels engages the perimeter edges to retain the first slide track insliding engagement with the connection plate, a second slide track, thesecond slide track including perimeter channels.

In one form, the second slide track perimeter channels engage the firstslide track perimeter channels in a sliding engagement.

In one form, the second slide track perimeter channels engage theexterior of the first slide track perimeter channels.

In one form, the monitor arm further includes a mechanism to selectivelyprevent sliding movement of the first slide track relative to theconnection plate. The mechanism includes a brake extending from anaperture in a face of the connection plate, a spring to bias the brakein contact with a face of the first slide track, and an actuator to movethe brake.

In one form, the first slide track and the second slide track are backto back. The second slide track is engaged in a sliding engagement witha second connection plate.

In one form, the monitor arm further includes a second arm. The secondarm is connected to a second connection plate. A third slide track is insliding engagement with the second connection plate. The third slidetrack and the first slide track are joined with a connector tointerconnect the first and third slide tracks.

In one form, the rotation limiter further includes a top bushing fitonto the outer rotational element and a bottom bushing. The top bushingand bottom bushing capture the first and second rings about the outerrotational element. The bottom bushing includes at least one key. Thekey extends from the bottom bushing into an aperture of the outerrotational element. The key prevents rotation of the bottom bushingabout the outer rotational element.

In one form, the top bushing includes a plurality of inner surfaceprotrusions extending towards the first ring. The first ring has asurface in contact with the plurality of protrusions. The first ringsurface includes indexing structures to interact with the inner surfaceprotrusions.

In one form the rotation limiter is removably coupled to a first monitorarm and a second monitor arm.

In one form the rotation limiter give a visual reference to the allowedrange of rotation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a prior art patent figure illustration of an exemplaryadjustable footrest in a first position.

FIG. 1B is a prior art patent figure illustration of an exemplaryadjustable footrest in a first position.

FIG. 2A is a prior art patent figure illustration of an exemplaryadjustable footrest in a first configuration as part of a sit standdesk.

FIG. 2B is a prior art patent figure illustration of an exemplaryadjustable footrest in a second configuration as part of a sit standdesk.

FIG. 3 is a prior art patent figure illustration of an exemplaryunder-desk footrest with motorized movement.

FIG. 4 is a prior art patent application figure illustration of anexemplary adjustable writing surface.

FIG. 5 is a prior art patent figure illustration of an exemplary laptopcomputer stand.

FIG. 6 is a rear perspective exploded view of the Multi-PositionalArticulating Ergonomic Device with Modular Features of the presentinvention.

FIG. 7 is a front or operator's point of view perspective view of theMulti-Positional Articulating Ergonomic Device with Modular Features ofthe present invention.

FIG. 8 is a series of sequential isometric side views of four diagramsof an actuation assembly sequentially illustrating how a rotationalrange controller functions.

FIG. 9A is a simplified isometric side view showing a footrestembodiment of the present invention in its upper range of movement.

FIG. 9B is a simplified isometric side view showing a footrestembodiment of the present invention in an optional range of movement andthe force feedback feature.

FIG. 10A is a simplified isometric side view showing the invention inthe footrest embodiment in a lower movement range setting position,illustrating the optional range of movement and the force feedbackfeature.

FIG. 10B is a simplified isometric side view showing the invention inthe footrest embodiment in a lowest movement range setting position,illustrating the optional range of movement and the force feedbackfeature.

FIG. 11 is a simplified isometric side view, showing the invention inthe footrest embodiment in the upper movement range setting position,illustrating the alternative use of a gas spring.

FIG. 12A is a simplified isometric side view showing the invention inthe writing surface embodiment in a raised position.

FIG. 12B is a simplified isometric side view showing the invention inthe writing surface embodiment.

FIG. 13A is a simplified isometric side view showing the invention inthe monitor arm embodiment in a lowered configuration.

FIG. 13B is a simplified isometric side view showing the invention inthe monitor arm embodiment in a raised configuration.

FIG. 13C is a simplified partial exploded side detailed view of theoptional slider connector of the monitor arm embodiment.

FIG. 13D is a simplified partial exploded side detailed view of theoptional slider connector of the monitor arm embodiment.

FIG. 13E is a simplified side detailed view of the optional sliderconnector of the monitor arm embodiment.

FIG. 13F is a simplified isometric front view showing how two sliderassemblies may be connected.

FIG. 14A is a simplified isometric side view showing the invention inthe modular laptop riser embodiment in the lowered configuration.

FIG. 14B is a simplified isometric side view showing the invention inthe modular laptop riser embodiment in the raised configurationrespectively.

FIG. 15 is a simplified isometric side view of an alternative embodimentof base assembly.

FIG. 16 is a simplified isometric side view, representing the inventionin the modular laptop riser embodiment in a construct which allows thearticulating armature assembly, to be attached to a monitor armassembly.

FIG. 17A is a simplified isometric side view showing the inventionsalternate embodiment replacing the assembly base with a clampingassembly for clamping on the edge of a support surface.

FIG. 17B is a simplified isometric side view showing the inventionsalternate embodiment replacing the assembly base with a clampingassembly for clamping on a support surface having a grommet or apertureand including aligned base aperture for cord management.

FIG. 18A is a simplified isometric side view of a user adjustablerotation limiter limiting counterclockwise rotation.

FIG. 18B is a simplified isometric side view of a user adjustablerotation limiter limiting clockwise rotation.

FIG. 19 is a perspective view of a monitor arm assembly including afirst slide track and a second slide track engaged over the perimeterchannels of the first slide track, the slide tracks in fully extendedpositions.

FIG. 20 is a partial side exploded side elevational view a monitor armassembly including a first slide track and a second slide track engagedover the perimeter channels of the first slide track.

FIG. 21 is a perspective view of a monitor arm assembly including afirst slide track and a second slide track engaged over the perimeterchannels of the first slide track, the slide tracks in centeredpositions.

FIG. 22 is a perspective view of a monitor arm assembly including afirst slide track and a second slide track engaged over the perimeterchannels of the first slide track, the first slide track in a fullyextended positions, and the second slide track in a centered position onthe first slide track.

FIG. 23 is a partial perspective exploded view of a monitor arm assemblyincluding a first slide track and a second slide track engaged over theperimeter channels of the first slide track, the slide tracks incentered positions.

FIG. 24 is a partial side elevational view of a monitor arm assemblywith a first slide track and a second slide track in a back to backrelationship.

FIG. 25 is a partial exploded view of FIG. 24 .

FIG. 26 is a partial perspective exploded view of a monitor arm assemblyincluding a first slide track and a second slide track back to backrelationship, the slide tracks in centered positions.

FIG. 27 is a partial perspective view of a monitor arm assemblyincluding a first slide track and a second slide track back to backrelationship, the first slide track in an extended position.

FIG. 28 is a partial perspective view of a monitor arm assemblyincluding a first slide track and a second slide track back to backrelationship, the first slide track in an extended position and themonitor bracket in an extended position in the second slide track.

FIG. 29 is a perspective view of a monitor arm assembly including afirst slide track and a second slide track engaged over the perimeterchannels of the first slide track, the slide tracks in centeredpositions, including an actuator for a brake.

FIG. 30 is a front elevational view of the monitor bracket, actuator,and slide assembly of FIG. 29 .

FIG. 31 is a cross sectional side elevational view of the assembly ofFIG. 30 .

FIG. 32 is an exploded view of a rotation limiter of the presentinvention.

FIG. 33 is a top sectional view of the assembled rotation limiter ofFIG. 32 .

FIG. 34 is a side perspective sectional view of the assembled rotationlimiter of FIG. 32 .

FIG. 35 an exploded view of another embodiment of rotation limiter ofthe present invention.

FIG. 36 is a top perspective view of the rotation limiter of FIG. 35 ,with the top bushing removed.

FIG. 37 is a top sectional view of the assembled rotation limiter ofFIG. 35 .

FIG. 38 is a side perspective sectional view of the assembled rotationlimiter of FIG. 35 .

FIG. 39 is a partial side perspective exploded view of a cassetterotation limiter with first and second arms of a monitor arm assembly.

FIG. 40 is a bottom perspective view of a limiter activator and topbushing having discontinuous channels and index protrusions.

FIG. 41 is a another bottom perspective view of a limiter activator andtop bushing having discontinuous channels and index protrusions.

FIG. 42 is a top perspective exploded view of a rotation limiter of thepresent invention, including a bushing with keys to prevent rotation ofthe busing relative to the outer rotational element.

FIG. 43 is a back elevational view of two monitor arm assembled with afirst and second slide track joined by a connector.

FIG. 44 is a back right side perspective view of the connected assemblyof FIG. 44 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the figures, the various details and embodiments ofthe invention are shown. One skilled in the art will recognize that dueto the modular nature of the assemblies described herein, many of thedetails may be applied to other embodiments even though they arediscussed with reference to a specific embodiment. FIG. 6 is athree-quarters exploded view of the Multi-Positional ArticulatingErgonomic Device with Modular Features of the present invention. Thedevice 100 is shown with footrest platform assembly 500 which includesplatform 510, gripping components 520, and curved front kickplate 515.The platform assembly 500 may include a TPU grommet in coupling to thearticulating armature assembly 400 to allow for some movement,deflection and adjustment of the platform 510 relative to the armatureassembly for the comfort of the user.

In some embodiments, the platform assembly 500 is supported by thearticulating armature assembly 400 which includes upper connection plate440, optional upper rotational bearing 430 (when rotation and pivotingmovement is desired) which is assembled to upper four-bar connectionplate 415 which links upper four-bar arm 410, lower four-bar arm 405 andlower four-bar connection plate 417 creating the articulating four-barmechanism.

The four-bar mechanism is optionally encased by upper encasement 425 andlower encasement 420. The four-bar mechanism assembly is then coupled tothe base assembly 200 by way of the optional lower rotational bearing435 (when additional rotation and pivoting movement is desired) which ifnot utilized, the base assembly 200 would then attach to the armatureassembly by way of the lower four-bar connection plate 330 only.

The lower four-bar connection plate also contains an armaturearticulation actuator assembly 300 consisting of a high force spring orother biasing element such as torsion spring 312, and a lower forcespring or biasing element such as torsion spring 307, the springs allowfor differentiating forces in the articulation range of the four-bararmature's movement ranges. In embodiments where a differentiating forceis not desired, a single spring element can be utilized in place of themultiple elements shown.

To initiate movement of the armature, an actuation lever is providedwhich would release the spring and engage the spring accordingly. Inthis embodiment, the two spring element's actuations are controlled byactuation lever 305 and 310 accordingly which are retained in lowerfour-bar connection plate 417 by way of retaining pin 314. Optionally,if stops or ranges of upward articulation of the four-bar mechanism isdesirous, rotational range controller 302 can be utilized to ensure theuser needs to re-actuate the springs as to control the sub-range ofmotions within the articulation movement of the four-bar assembly.Rotation damper 360, range controller 302 and torsion springs 307 and312 can be assembled by machine screw and washer 325 to slow theexpansion of the spring elements by way of an internal assembly ofplates and damper grease within damper 360 to slow down the upwardsmovement of the four-bar assembly 400 and the attached upper platformassembly 500.

In some embodiments, the base assembly 200 includes a base unit 205,gripping elements 210 of which there can be a plurality placed on theunderside of base unit 205. Optional slide plate 220 is also attached tothe underside of base unit 205 allowing the unit to be moved easily bylifting the unit by the kickplate 515 and pivoting or tilting the uniton the slide plate 220, allowing slide plate 220 to make primary contactwith the floor or other working surface to easily move the unit untillowered as to then allow gripping elements 210 to make primary contactwith the floor securing the unit from nonintentional movement.

In some embodiments as shown in FIG. 7 , the device 100 is shown withfootrest assembly 500 moveably coupled onto the articulating armature400. Raising and lowering of the unit is controlled by actuationassembly 300, which includes machine screw 325 which allows thearticulating armature 400 to be moveably attached to base assembly 200.

The actuation assembly 300 allows for a multitude of movement rangeswhich allows for example, a sitting range and a standing range. Betweenthose set ranges, platform 510 can be moved with a downward forceallowing the counter sprung articulating armature 400 to counter theforce; this action allows and encourages the operator's legs to stretch,feet and ankles to move without having to constantly readjust the footrest's height or spring tension. If too much force is exerted onto thearmature 400 or footrest platform 510, actuation assembly 300 has aclutching safety feature to discourage using the footrest as a step.

FIG. 8 a simplified isometric side view of four figures of actuationassembly 300 sequentially illustrating how rotational range controller302 functions. The top figure in the sequence of figures represents theassembly as it would be in the lowered position of two positions asrepresented in this embodiment; range controller 302 position notch 302a is engaged with actuation lever 305. Torsion spring 307 provides foradditional range of motion within this position while exerting acounterforce when a rotational force is enacted on the rotational rangecontroller.

In the next following sequential figure, actuation lever 305 isdepressed, disengaging the actuation lever retainer detail from positionnotch 302 a. In the next following sequentially lower figure, rotationalrange controller 302 has been rotated clockwise, placing position notch302 b above the retainer detail of actuation lever 305. In the nextfollowing sequential and lowest figure, position notch 302 b is fullyengaged and actuation lever 305 is returned to its raised non-depressedposition. In this position, the assembly would be in the higher of thetwo positions with torsion spring 307 providing for additional range ofmotion within this position while exerting a counterforce when arotational force is enacted on the rotational range controller.

This embodiment illustrates how the actuation assembly 300 with therange controller 302 actuates and controls the lower zone of movement ofthe device 100 as well as provide actuation and control in the upperranges of movement as well. Even though in this embodiment, only tworanges are shown, additional positional notches could be implemented orremoved to provide an assembly, such as an articulating support arm withmultitudes of positions, ranges of movement with and without forcefeedback within those positions. One will recognize that there may bemultiple ranges of motion, and that each range may be limited or definedby a separate range controller or range controller mechanism. Forinstance, if the embodiment were to have three ranges of elevation, eachrange may have its own range controller and may have its own spring, gasstrut, or other biasing member and respective actuator to selectivelyprovide counterforce.

An exemplary upper range of movement for a footrest embodiment is shownin FIG. 9A and a lower range of movement is shown in FIG. 9B. Thisillustrates the optional range of movement and the force feedbackfeature within an upper movement range setting. For example, an operatorwould be in a standing position with one foot resting on the upper sideof platform assembly 500. FIG. 9A represents the unit with little or noforce or weight applied in the upper movement range setting. As weightis applied to footrest platform 510, upper armature 410 exerts forceupon torsion spring 307 which acts as a counterforce to the appliedforce or weight. This counterforce allows the operator to interact withthe footrest as to engage with the unit further by applying additionalweight and/or additional force; these additional forces engage thetorsion spring by way of the articulation armature 400 rotating thetorsion spring further into its range of motion and when the additionalforces disengage, counter rotating the torsion spring in response to thelessening weight or force. These actions allow platform 510 to stayengaged with the operator and move in direct response operator's actionsin a way as to support not only the natural weight exerted onto theunit, but the additional forces exerted by the operator as to give way(platform 500 lowers) while pushing back (upwards) with a counteringforce by way of the articulating armature 400 and actuation assembly300's torsion spring 307. This giving way and counterforce is intendedto allow the operator to engage with the footrest platform 510 usingmore natural movements which stimulates the operator's joints andmuscles versus a device which is more stagnant and rigid in form. Whilethis example has the operator standing, the same action utilized whilesitting as well. Further, the footrest may be used to allow a user tohave a surface on which to place her feet, for example when sitting in araised chair, or those whom need the higher setting for proper ergonomicpositioning, or those whom want to interact with the footrest in a moreactive way.

FIGS. 10A and 10B illustrate the invention in the footrest embodiment inthe lower movement range setting position, illustrating the optionalrange of movement and the force feedback feature within that lowerposition setting. This lower position setting is representative of theinvention in the embodiment of a footrest which is being used in thesitting position or a lower setting range for a standing position.Whereas the operator would be sitting in an office chair with either oneor both feet resting on the upper surface of platform assembly 500 ormay be standing with one foot resting on the platform in its lowermovement range setting.

In some embodiments as shown in FIG. 11 the invention may in thealternative use a gas spring 308 moveably attached to upper four bar arm410 and lower connection plate 417, in place of the torsion springarrangement previously disclosed. The actuation assembly 300 includesactuator 306 which actuates the lowering and raising of the unit bydepressing the gas spring's valve mechanism allowing the gas spring's308 telescoping member to extended in the raising mode or be contractedin a lowering mode. This actuator 306 may include a force adjustmentscrew which adjusts the force exerted by gas spring 308 to ensure theproper countering force is exerted as to ensure the units functionality,which in this case, is the footrest embodiment. In other embodiments,the force setting required might be less or greater depending on how theunit is configured and how much force or weight is applied to the gasspring.

In some embodiments the device may include a writing surface asillustrated in FIGS. 12A and 12B. FIGS. 12A and 12B illustrate theinvention in the writing surface embodiment in the raised and loweredconfiguration respectively. FIGS. 12A and 12 B show the commonly sharedbase assembly 200, armature actuation assembly 300 with the articulatingarmature assembly 400 is in a raised position. This raised positionallows writing surface 700 to be at a greater slope as compared to thesurface in which the unit rests.

In some embodiments writing surface 700 can be pivoted in the plane ofthe writing surface 700 by way of upper and or lower rotational bearing430 and 435 respectively. Typical writing surfaces do not have theability to rotate as to accommodate right-hand or left-hand orientationthus making this configuration much more conducive to answering theergonomic needs of such a device.

Writing surface 700 is shown with writing instrument holder 720 andresting edge 715 which is sloped as to accommodate a transition for thewrist and a contact point as to ensure stability if one would leanagainst the surface. FIG. 12B represents the writing surface embodimentin the lowered configuration, whereas actuation lever 305 has beenutilized to allow the unit's writing surface 700 to reside lower andtherefor at a less angle as compared to the surface the unit is restingupon.

FIGS. 13A-F illustrate embodiments of the invention in a monitor armembodiment in the raised and lowered configuration along with a moredetailed view of an optional sliding connector. FIGS. 18-42 also showfeatures of the inventions disclosed herein that may be used in monitorarm assemblies. On skilled in the art will recognize that monitor armassemblies may include joints that rotate in the vertical plane as wellas joints that rotate in the horizontal plane. The teachings of theinventions herein may be used in many monitor arms, and not limited tothe specific embodiments shown herein. Further, the teachings throughoutthis disclosure may be used in other devices and assemblies.

In FIGS. 13A-F, modular monitor arm assembly 700 is coupled toarticulating armature 720 which is coupled to connection plate 440 andto the rest of the unit, including articulating armature assembly 400,actuator assembly 300 and base assembly 200 allowing for a monitor armconfiguration to rest upon a surface in this configuration. In otherconfigurations base assembly 200 can be replaced by a desk or tableclamp system if desired.

Armature 720 can be constructed similarly to articulating armatureassembly 400 using an articulating four-bar mechanism or can be of asimpler construct of being slidably attached to upper connection plate440 as to allow monitor 750 to move away from and towards the operator.Along with the optional slidable attachment means, articulatingconnection plate 415 and monitor connection plate 710 allow for pivotaland optionally rotational movement. The pivotal articulating connectionplate allow the monitors viewable area to be articulated in an upwards,downward, in and out, as well as pivotal movements.

FIG. 13B shows the modular monitor arm assembly in a raised position.FIG. 13C shows the optional slider connector 715 assembly which wouldallow the monitor 750 to be adjusted in a side to side movement and orwhen pivoted ninety degrees, in an up and down rotational movement byway of articulating pivot connector 713 as well. The slider connectorassembly 715 can have a multitude or plurality of tracks, as shown withexemplary slide track 711 and slide track 712, in which the connectionplate 710 and monitor 750 would then be slidably connected to slide sideto side with each connection plate being independently slid if desired.Knurl knobs or Allen wrench screws or other selectively releasablemechanisms are utilized to lock the slidable connection plates in thedesired locations, or free them for adjustment.

In some embodiments as shown in FIGS. 19-31 , the slider connectorassembly may include a connection plate 710 slidably captured by a firstslide track 711 in a slidable relationship in a lateral direction L. Oneskilled in the art will recognize that the lateral or side to sidedirection is with reference to the connection plate 710. As oriented inthe figures, the lateral direction L may be considered side to side.When the connection plate 710 is reoriented 90 degrees, the directionmay be considered up U and down D or top and bottom.

The connection plate 710 may include a first face 7101. The first faceopposes or faces the first slide track 711 in the assembled device. Thefirst slide track may include a first face 7111. The first slide trackfirst face 7111 faces or opposed the connection plate 710.

The connection plate 710 and the first slide track may be coupled toeach other in a sliding relationship. The connection plate is generallya rectangular plate. In some embodiments, the connection plate includesperimeter edges 7105 and 7106. The perimeter edges are generallyparallel to each other. In some embodiments, the perimeter edges aretapered. In some embodiments, the perimeter edges 7105 and 7106 areshaped to be complimentary to perimeter channels 7115 and 7116 on thefirst slide track 711. The coupling of the perimeter edges and theperimeter channels couple or capture the connection plate 710 and firstslide track 711 is a sliding relationship.

In some embodiments, the connection plate first face 7101 includes afirst guide channel 7103 and a second guide channel 7104. The first andsecond guide channels may be parallel to the perimeter edges 7105 and7106. The first slide track first face 7111 may include protrusions orother opposing structures to engage the first and second guide channels7103 and 7104. Such other structures may include fasteners placedthrough apertures in the first slide track 711. The protrusions may beshaped complementary to the first or second guide channel so as to becaptured by the guide channels and allow the first slide track 711 toslide laterally with respect to the connector plate 710, but restrainedin directions normal to the opposing faces of the connector plate 710and first slide track 711, as noted by direction N. The first and secondguide channels may also accept the protrusions without capturing them toresist movement in the N direction. In any embodiment, the guide tracksand protrusions may assist in bearing weight in a downward direction toreduce the downward load and sliding resistance on any individualchannel, guide, or sliding component. The first slide track 711 may betranslated with respect to the connector plate 710. In some embodiments,the protrusions or apertures or other structures are located within theperimeter channels 7115 and 7116.

In some embodiments, the sliding relationship between the connectionplate 710 and the first slide track 711 is controlled by a skid or brake7150, shown in cross-section in FIG. 30 . The brake 7150 may beconnected to an actuation mechanism, including an actuator or button7155, a spring 7160, and a linkage 7170. The spring 7160 may bias thebutton 7155 in a position flush with a housing attached to theconnection plate 710. The spring 7160 may also bias the brake 7150 in anactivated position wherein the brake is in contact with the first slidetrack 711. The brake may be in contact with the first face 7111 of thefirst slide track 711 to prevent movement of the first slide track 711relative to the connection plate 710. In some embodiments, the brake mayextend and retract from an aperture 7190 in the connection plate 710.

In operation, movement of the button 7155 against the bias of the spring7160 moves the linkage 7170 about a pivot, withdrawing the brake fromcontact with the first face 7111 of the first slide track 711. Releaseof the button 7155 allows the bias of the spring 7160 to return thelinkage 7170 and the brake 7150 to the engaged position. While the brake7150 is disengaged, the user may move the slide track 711 to a desiredposition before returning the brake 7150 to the engaged position.

In some embodiments, the perimeter channels 7115 and 7116 are atruncated V shape. In other embodiments they may be of any shape thatallows capture or restraint of the connector plate 710 in the Ndirection. The perimeter channels may also allow translation movement ofthe connector plate 711. One wall of the perimeter channels may extendfrom the first perimeter channel 7115 to the second perimeter channel7116. Put another way, one of the walls of the perimeter channels are aportion of the first slide track first face 7111. The perimeter channels7115 and 7116 run in the L direction.

In some embodiments, the first slide track 711 and the connector plate710 are of the same lateral width. Put another way, the first slidetrack 711 and connector plate are generally of the same dimension orwidth in the L direction.

The first slide track 711 may be connected to another assembly as anapplication may see fit, such as a pivot connector, plate, or otherassembly to allow the connection of a monitor. A simple bracket toattach the monitor may also be used if a pivoting arrangement is notdesired. Other assemblies or objects may also be directly attached tothe first slide track 711.

In some embodiments, a second slide track 712 is coupled to the firstslide track 711. The second slide track 712 includes a second slidetrack first perimeter channel 7121 and a second slide track secondperimeter channel 7122. The second slide track perimeter channels 7121and 7122 are shaped to fit over and capture the first slide track 711 ina slidable relationship. The fit or tolerance will allow the secondslide track 712 to move laterally in the L direction but to berestrained in movement in the N direction. The interior shape of thefirst and second perimeter channels 7121 and 7122 of the second slidetrack 712 may be complementary of the exterior shape of the first andsecond perimeter channels 7115 and 7116 of the first slide track 711.

The second slide track 712 may be coextensive with the first slide track711 in the L direction. In other embodiments, the second slide track 712may be shorter in the L direction. The first and second perimeterchannels 7121 and 7122 may be continuous or discontinuous.

In some embodiments, the first slide track 711 has a second face 7112.The second face 7112 may be considered the exterior, outer, or backsurface of the first slide track 711. The second face 7112 may face awayfrom the connector plate 710. The second face 7112 opposes the interior,inner, or front surface of the second slide track 712.

In some embodiments, the second slide track 712 may include anadjustment mechanism 7125 to allow the movement of the second slidetrack with respect to the first slide track 711 to be selectively fixedor limited. In some embodiments, the mechanism may be a set screw. Othermechanisms as described or shown in the figures may also be used.

FIG. 13D and FIGS. 23-27 illustrate an alternate embodiment of theoptional slider connector 715 assembly with an exposed adjustmentmechanism which would allow the monitor 750 to be slidably adjusted andlimited. The slider connector assembly 715 in this embodiment having amultitude of tracks, slide track 711 and slide track 712 are configuredto be back to back, in which the connection plate 710 and monitormounting plate assembly connector 717 would then be slidably connectedto slide side to side independently within the corresponding slidetracks. The multitude of slide tracks allow the sliding movement to besequential in nature and as to take up less room than having to utilizethe same amount of movement in a single-track arrangement.

Knurl knobs or Allen wrench screws or other selectively releasablemechanisms may be utilized to control the sequential movement and orlock the slidable connection plates in the desired locations dependingon how the operator has set the resistance mechanism settings. In thisparticular embodiment two adjustment methods are shown, adjustment 730which utilizes but not limited to, a threaded insert screw into slidetrack 712 as a means to apply force onto plate connector 717 to impedeits side to side or lateral movement; the other is adjustment 740 whichutilizes a depressible actuator 741 with spring 743 biasing resistanceskid 745 to apply force in unison with connector plate 710, travelingwithin slide track 711 to impede its side to side movement. Bothadjustment mechanisms 730 by way of the adjustment knob or screw and 740by way of adjustment knob or screw compressing the force spring 743 asto exert more force are exemplary of ways to regulate the force neededto sequentially control the lateral sliding movement with the tracks 711and 712. Other methods to create hard stops can utilize such as anengagement pin registering into a hole or notch or any number of othersimilar methods if detent registrations and hard stops are desired.

FIG. 13E is a simplified isometric side view of the previous explodedview in the assembled form with both exemplary adjustment mechanisms 730and 740 are shown. One or the other method can be used interchangeablyand with the addition of added detents and hard stops.

FIG. 13F and FIGS. 43 and 44 illustrates a front view showing two of theaforementioned slider assemblies being connected by the use of connector737. One skilled in the art will recognize that the componentsdesignated with “a” are duplicate components in the connected assembly,such as first slide track 711 in one assembly and 711 a in the secondassembly. On skilled in the art will also recognize that the assembliesbeing joined do not need to the same or have one to one correspondenceof components. A two slide track assembly may be connected to a singleslide track assembly, etc. For purposes of discussing the figures theymay be referred to as left and right slider assemblies. For example, theconnector 737 may be used with the single slide track embodiment in FIG.13C, or with the back to back embodiments of FIGS. 13D and 13E. Howeverwhen used with the single slide track embodiment, or a back to backslide track arrangement, the connector plate 710 will not be able toslide to the adjacent slider assembly, as the connector 737 or slidetrack connector, will be in the way. Such an embodiment is shown inFIGS. 43 and 44 . However such embodiment would allow a second slidetrack that fits over a first slide track, such as that shown in FIG. 13Cto be used, and to transit from one adjacent first slide track to theother. Such is the case in FIGS. 43 and 44 , where the second slidetracks 712 and 712 a may slide onto adjoined or connected first slidetracks 711 and 711 a.

When used with the back to back embodiment, the connector 737 may beplaced in one of the slide tracks, such as the second track 712 or theslide track facing away in the FIG. 13F, while the connector plate 710for the arm assembly may be placed in the other of the back to backslide tracks. In FIG. 13F, the connector plate 710 is placed in thenearer of the back to back tracks. Due to the plurality of slide tracks,the tracks can be interconnected by way of a connection plate such asthe one illustrated, connector 737 which is partially slid into slidetrack 711 (rearward of track 712 shown) of both the right and leftassemblies as shown. The interconnected tracks allow plate connector 737to slide from the left assembly to the right and anywhere in-between.Since the connector 737 may also slide within the slide tracks intowhich it is inserted, the slide tracks may be spaced apart, as shown inFIGS. 43 and 44 , or in contact as shown in FIG. 13F. This type ofjoined configuration has the advantages of creating both a single,double (as shown in FIGS. 43 and 44 ), and larger articulating monitorarm assembly, but also allows these assemblies to interconnect and workin unison for easer adjustments and proper ergonomic articulation.Another stated advantage is the ability to offer a hybrid type ofmonitor arm system which can stand freely and as the user's needsprogress, move towards the advantages of a track based multi-monitorsupport system without having the operator completely change out theirexisting system giving them an entire range of executable configurationsnever offered in this type of product line.

FIG. 14A and FIG. 14B illustrate the invention in the modular laptopriser embodiment in the lowered and raised configuration respectively.In some embodiments, the laptop riser platform assembly 600 is attachedor coupled by way of connection plate 440 and to the rest of the unit,including the articulating armature assembly 400, actuator assembly 300and base assembly 200 allowing for laptop riser embodiment to rest upona surface in this configuration.

In some embodiments the base assembly 200 can be replaced by a desk ortable clamp system if desirous. As shown in FIG. 14A laptop 650 rests onriser surface 610 and is retained passively by surface griping elements,such as a textured thermal elastomer or other structures to resistmovement of a laptop computer or other device, and upturned retainer 615which prevents the laptop from sliding off the riser surface. Thesurface can be designed to allow air to flow from the sides or fromunder riser surface 610 by way of textured ribs or openings through theriser surface itself. In other embodiments, more active retainingelements may be used such as hook and loop latching strap mechanism oran articulating hinged retaining flap to encase the laptop partially asto secure it even when the raiser surface is at an aggressive position,such as when the riser surface 610 is raised and angled beyond aforty-five-degrees by pivoting upper four-bar connection plate 415. FIG.14B is a simplified isometric side view of the unit showing the modularlaptop riser embodiment in a raised position.

FIG. 15 illustrates an alternate embodiment of base assembly 200 for usewith the inventions disclosed herein. Base foot element 213 isconstructed with an elastomeric material formed to create a suction cupdesign as to ensure base foot element's 213 ability to grip to thesurface on which it is positioned or pressed to.

In some embodiments, the base foot element 213 is coupled to base 205 byan optionally pivotal assembly 212. With those elements, when weight islifted off foot 221, base 205 is able to pivot around pivotal assembly212 allowing any of the modular assemblies attached to the base to pivotas well about the pivotal assembly 212. Alternatively, base foot element213 could be utilized to replace all of the foot elements, such as 221to create a base assembly which is very stable and is removably appliedby suction and adhesion to the surface in which its attached. Thisconstruction adds stability without having to be clamped to the surfaceof a desk or table.

As shown in FIG. 16 , the invention in the modular laptop riserembodiment may include an articulating armature assembly 400, to beattached to a monitor arm assembly. Base assembly 200 may be removed andpole mount assembly 202 attached by way of lower four-bar connectionplate 417. Using the modular laptop riser embodiment is for illustrativepurposes and can be applied to other configurations if it is desirous toutilize any of the optional embodiments in pole mounted configuration.

With reference to FIGS. 17A and 17B, in some embodiments the assemblybase of the previous embodiments may be replaced with clamp assembly800. FIG. 17A illustrates the clamp assembly in edge clampconfiguration. Clamp bracket 820 coupled to clamp base 810 as to havethe distal ends of clamp bracket 820 facing towards the center of base810 for edge clamping configuration. In this configuration a table ordesktop 910 is clamped within bracket 820 with press foot 830 screwedtightly using knurl knob 850 which is attached to threaded rod element840. The remaining modular configurations can be added or connected tothe clamp assembly 800 by way of pole mount assembly 202.

In some embodiments, exemplified in FIG. 17B the clamp assembly may bein an aperture or grommet mount configuration. Clamp bracket 820 isassembled to clamp base 810 as to have the distal ends of bracket 820facing towards the outside with vertical element of bracket 820 goingthrough the grommet opening 920 with the table or desk top 910 isclamped within the bracket using the same method as previouslydescribed. Clamp base 810 has a cable opening 217 which should alignwith grommet opening 920 as to allow cabling to travel from under thetable or desktop through the grommet opening 920 and cable opening 217to the top of the table or desktop surface.

In some embodiments, a user adjustable rotation limiter may be included,as illustrated in FIGS. 18A and 18B. In such an embodiment, innerrotation element 436 rotates within outer rotational element 439. Limitrib 436 b is attached to and rotates with inner rotation element 436.Limiter tabs 437 a, 437 b, 437 c and 437 d can be pushed in towards thecenter to limit the rotational travel of limit rib 436 b. Similarly, thelimiter tabs can be pulled out to disengage the limiters.

FIG. 18A illustrates how counterclockwise rotation is limited whenlimiter tab 437 is engaged. FIG. 18B illustrates how the clockwiserotation is limited when limiter tab 437 is engaged. The more limitertabs are engaged, the more restricted the clockwise and counterclockwiserotation of the inner rotation element 436. The limiter tabs can bepulled out and disengaged as to increase the allowable rotation as well.The limiter tabs move in and out by way of corresponding limit tabguides 438 a, 438 b, 438 c and 438 d.

One skilled in the art will recognize the inner rotational element 436and outer rotational element 439 may rotate with respect to each otherwhile one or both of them are fixed or stationary with respect tosomething else, such as a base, monitor arm, or other structure of anassembly. Further, the use of “inner” and “outer” are terms used withreference to the rotational elements, and not absolute terms. The outerrotational element does not have to be the outermost element of anassembly. For instance, in some embodiments, the outer rotationalelement 439 is inward of a limiter activator 441.

In some embodiments, the rotation limiter may include activators toactivate or engage and disengage the tabs or other structures such aspins. The activators may be a ring or plurality of rings, collars, orother structures placed about the tabs or pins that a user maymanipulate to activate or selectively engage the tabs or pins or otherstructures.

In some embodiments as shown in FIGS. 32-42 , the rotation limiter 100may be constructed utilizing movable pins 437 or rollers. The rotationlimiter includes an outer rotational element 439, an inner rotationalelement 436, a limit rib 436 b attached to the rotational element, aplurality of pins 437, rollers or limiter tabs, pin guides 438, and alimiter activator 441. Some embodiments may include a plurality oflimiter activators such as a second limiter activator 442.

The pins or rollers may be of any convenient construction to allow themechanisms to rotate and allow the pins to be moved into and out of pinguides. In the most preferred embodiments, the pins 437 are cylindricalwith a major axis, with tapered tops and bottoms. The taper may betruncated.

The limiter activator 441 may be a ring structure that is rotatableabout the limiter pins and limiter pin guides. The limiter activator mayinclude a protrusion 443 to move, displace, or otherwise interact withthe limiter pins 437. The protrusion 443 may be located on the innerfacing surface of the limiter activator 441. The limiter activatorprotrusion 443 may include a ramp or transition area 444 on either sideof the protrusion 443 to allow for smoother rotation of the limiteractivator 441 and smoother activation or engagement of the pins 437. Thesecond limiter activator 442 may be similarly constructed and have thesame features and similar function to the limiter activator 441.

The pin guides 438 may be a cage or plurality of slots or apertures toaccept the pins and may be part of the outer rotational element 439. Thepin guides 438 are circumferential and define apertures or spacestherebetween to accept the pins 437. The pin guides may have wall thatare tapered in a radial direction. Such tapering may be viewed as atruncated wedge shape in cross section. The tapering wall thus definethe apertures to have a greater width radially closer to the center ofthe pin cage, or closer to the axis of rotation. It is preferred thatthe tapered walls prevent the pins 437 from completely passing throughthe apertures. Put another way, the minimum spacing between the taperedwalls defining an aperture is less than the width of a pin 437.

The outer rotational element 439 may be referred to as a pin cage. Theouter rotational element 439 may be attached to or be in a frictionengagement with an assembly, base, or other structure that it isdesirous to have the structure or device attached to the innerrotational element 436 rotate with respect to.

In some embodiments, the limiter pins 437 may be eliminated and the pinfunction replaced with the pin cage or outer rotational member 439having tabs. In such an embodiment, the pin cage tabs are displaceablein part by flexing in an inward direction via interaction with theprotrusion 443 on the limiter activator 441. So displaced, the pin cagetabs interfere with the protrusions or limit rib 436 b on the innerrotational element 436 to selectively limit rotation.

In some embodiments, the outer rotational element 439, the innerrotational element 436, and a limiter activator 441 and 442 arecoaxially aligned. The pins 437 and guides 438 are located between theoutside of the inner rotational element 436 and the limiter activators441 and 442. The inner rotational element 436 may include a top flange436 a or a bottom flange 436 c. The top flange 436 a or bottom flange436 c may extend over the pins 437, but such extension is not necessary.

In some embodiments, the rotation limiter includes an inner rotationalelement 436 including a flange with a bottom facing annular channel 471.The annular channel receives a top bushing 450. The top bushing 450 whenseated in the annular channel 471 spaces the first limiter activator 441away from the outer rotational element 439. The top bushing 450 may bean anti-friction bushing to improve rotation.

The first limiter activator 441 and the second limiter activator 442 mayinclude opposing facing annular channels to receive a linking ring 470.In some embodiments, the linking ring 470 may be attached to one or theother of the first limiter activator 441 or the second limiter activator442. The linking ring 470 may be constructed of a low friction material.

In some embodiments the limiter activators 441 and 442 may be separatedby a bushing, washer, or other structure to separate the limiteractivators or to prevent them from touching each other. One skilled inthe art will recognize that the structure discussed and shown in thedrawings as the linking ring 470 may also be considered a washer,bushing, or other structure separating the first and second limiteractivators. One skilled in the art will also recognize that the linkingring 470 may be utilized between any number of limiter activators, suchas between a second and third limiter activator in embodiments withthree limiter activators.

The assembly may include a bottom bushing 473 located below the secondlimiter activator 442 to space the second limiter activator 442 from theouter rotational element 436 and allow the limiter activators 441 tomaintain a uniform distance from the outer rotational element andprovide for smooth and concentric rotation of the assembly. The assemblymay also include locking ring halves 476 a and 476 b to retain the outerrotational element between the flanges of the inner rotational element.The top 450 and bottom 473 bushing allow the inner and outer rotationalelements to rotate with respect to the limiter activators and in thecase of the top bushing 450 to one another and preferably are made of anon-friction material that permits a sliding relationship. The assemblymay also include a bushing 474 between the inner rotational elementbottom flange 436 c and the locking ring 476 a and b.

The inner rotational element 436 has a central area, recess, or aperture488 to accept an assembly, such as a monitor arm or platform linkage,though any assembly that is desired to be rotated and limited inrotation may be attached.

As shown in FIGS. 32-42 the rotation limiter 100 may be constructed as acartridge assembly that may be placed between two structures, such asbetween two arms 720 of a monitor arm assembly. One skilled in the artwill recognize that the two arms are merely exemplary, and the rotationlimiter may be used between other structures, including an arm and abase. As shown in FIG. 39 the lower arm 120 includes an aperture 122 toaccept a post 150, lead-in, or other structure to rotatably connect thelower arm 120 with the upper arm 130. The aperture is sized to receivethe post 150, but also allow the post to rotate within the lower arm120. The rotation limiter 100 cartridge may be replaced with by a spaceror simple bearing in assemblies not desiring rotation limitation.

In some embodiments, the post 150 includes an area of reduced diameter151 or radial thickness. The area of reduced thickness includes a rampor tapered section 152. The tapered section 152 leads from a constantdiameter upper section 156 to a reduced diameter section 151.

In some embodiments, as shown in FIGS. 34-39 the inner rotationalelement 436 may include a boss 820, tab, or other structure to engagewith a post 150, lead-in, or other structure of the monitor arm,platform linkage, or assembly. In such embodiments, the post, lead-in,or other structure of the monitor arm, platform linkage, or assembly mayinclude a receiver 822 or complementary notch to engage, receive, orinteract with the tab or boss 820, allowing the post, lead-in, or otherstructure to cause rotation or rotate with the inner rotational element436. In the most preferred embodiment, the receiver 822 or notch hasvertical walls or walls that are perpendicular to the direction ofrotation to prevent any upward forces that may tend to displace thepost, lead-in, or assembly from the inner rotational element 436. Inother embodiments, the walls may taper upward to provide a guiding orcentering force when the post, lead-in, or other assembly is placed intothe aperture 488.

Similarly, the rotation limiter outer rotational element 439 may includestructure to engage another assembly such as a base or monitor arm toprevent rotation between or rotationally couple the outer rotationalelement 439 and the structure. In some embodiments, the structure is alinking pin 499 that fits a receiver 498 in the bottom of the outerrotational element 439 and into an aperture or structure in theassembly, such as a monitor arm. In other embodiments, the bottom of theouter rotational element 439 may include a boss 844 or other structureto engage a receiver 840 in the assembly, such as lower monitor arm 120.The top bushing 450 may include a receiver 847 to receive a protrusion822, boss, or other structure to prevent rotation between orrotationally couple the outer rotational element 439 and the upper arm130.

In some embodiments, the tab or boss 820 is positioned on the inside, orthe side facing the center axis of the inner rotational element 436. Insome embodiments the boss 820 is positioned in the lower half of theinner rotational element 436. In some embodiments, the tab or boss 820is positioned at least partly in the upper half of the inner rotationalelement 436. The tab or boss 820 may also span from 1 to 35 degrees ofthe surface of the inner rotational element 436. In some embodiments thetab or boss 820 may be non-continuous, being a series of spaced apartsplines. In some embodiments, the splines are present for more than 35degrees of the surface of the inner rotational element.

In some embodiments, the tab or boss 820 protrudes from the surface ofthe inner rotational element 436 towards the axis of the innerrotational element. The tab may include side walls that are parallel tothe axis 1000 of the inner rotational element 436. The side walls mayinclude an angled or tapered upper portion, the tapering or angled wallsbeing at an angle to the axis 1000. The angled walls may meet at avertex or may be truncated. The narrowing of the boss 820 created by theangled walls provides a centering guide to help align the tab or boss820 with the receiver 822 as the post 150 or lead-in is placed into theinner rotational element 436.

As further shown in FIGS. 34-41 , the rotation limiter 100 may be in theform of a cassette. The embodiments of the rotation limiter shown inother figures may also be in the form of a cassette. The rotationlimiter assembly in some embodiments may include a top bushing 450 pressfit onto the top of the outer rotational element 439 or pin cage. Suchplacement may make the rotation limiter a contained unit. In suchembodiments, the top flange of the inner rotational element 436 may bereduced in radial size, displaced from the top rim of the innerrotational element, or eliminated. The top bushing 450 may include achannel 451 to accommodate the tops of the pin guides 438 or pin cage.The top bushing 450 and pin cage 438 are preferably a friction fit toretain the top bushing 450 onto the pin cage 438 or outer rotationalelement 438. The channel 451 in the top bushing 450 may be continuous ordiscontinuous.

The top bushing 450 radially overlaps the first limiter activator 441 toretain the limiter activator 441 in the assembly. In some embodimentsthe overlap is provided by an outer radial flange 450 a on the outsidecircumference of the top bushing 450. The top bushing 450 may alsoinclude an inner radial flange 450 b on the inside circumference toretain or capture the inner rotational element 436. It is preferably tohave rotational friction between the first limiter activator 441 and thetop bushing 450 to provide smooth rotational feel.

In some embodiments the pins 437 are captured or located between theunder surface of the top bushing 450 and bottom portion of the outerrotational element 439. The vertical movement of the pins 437 may beminimized. The pins 437 may contact both the under surface of the topbushing 450 and the top surface of the bottom portion of the outerrotational element 439 to minimize or eliminate vertical movement of thepins within the pin cage or apertures.

In some embodiments the inner rotational element 436 includes a flange436 a on the outer circumference, the flange displaced from the topedge. The inner rotational element flange 436 a engages a recess,channel, notch, shelf or other structure present on the top bushing toprevent the upward movement of the inner rotational element, therebycapturing the inner rotational element between the top bushing and theouter rotational element.

In some embodiments, the bottom portion of the outer rotational element439 includes a flange 439 a in contact with the bottom of the innerrotational element. The flange 439 a is in the inward direction. Theflange 439 a of the outer rotational element 439 captures or preventsthe downward movement of the inner rotational element 436 when therotation limiter is assembled.

In some embodiments, the rotation limiter 100 assembly includes anintermediate bushing 455. The intermediate bushing 455 includes acentral aperture wide enough to allow the intermediate bushing 455 tofit over the pin cage and be positioned on a bottom outer flange 439 bof the outer rotational element 439. In such an embodiment, theintermediate bushing 455 is located about the outer circumference of thepin guides 438.

In some embodiments, it is preferable for the intermediate bushing 455to not rotate with respect to the outer rotational element 439 or withrespect to the pin guides 438. This allows the limiter activator 442 tobear against the outer circumference of the intermediate bushing 455without the intermediate bushing 455 b rotating, providing a constantamount of resistance and feel to the rotation of the limiter activator442. The bottom bushing includes a plurality of inwardly facingprotrusions or keys 457. The keys 457 are sized to fit into theapertures of the pin cage.

In some embodiments, the apertures of the pin cage that are to acceptthe keys 457 are sized larger in a vertical direction than the otherapertures so as to accommodate the added vertical thickness of the keys457. Thus the vertical dimension of the apertures with the keys 457 inplace is the same as the vertical dimension of the apertures that do notaccept the keys 457. This arrangement allows the same sized pins 437 tobe used in each aperture. In some embodiments, the apertures may besized the same, and the apertures that accept the keys 457 use pins 437with a smaller vertical dimension to accommodate the added thickness ofthe keys 457.

In some embodiments, the first limiter activator 441 and second limiteractivator 442 are positioned about the outer rotational element 439 in acoaxial arrangement. The first limiter activator 441 includes a notch441 a, groove, shelf or other structure to engage a flange 450 c of thetop bushing 450, thereby preventing the first limiter activator 441 frompassing over the top bushing 450, thereby retaining the first limiteractivator 441 about the outer rotational element 439. The first rotationlimiter 441 is free to rotate with respect to the flange 450 c of thetop bushing 450.

In some embodiments, the bottom surface 441 b of the first limiteractivator 441 is in contact with the top surface 442 b of the secondlimiter activator 442. The second limiter activator 442 includes a notch442 a, groove, shelf or other structure to engage the intermediatebushing 555 flange or the outer flange 439 b of the outer rotationalelement 439. So engaged, the second limiter activator 442 will not passbelow or off of the outer rotational element 439 in the downwarddirection. With such a construction, the first limiter activator 441 andthe second limiter activator 442 are captured between the top bushing450 and intermediate bushing 450 or flange 439 b of the outer rotationalelement 439.

In some embodiments, the inner rotational element 436 may include adisplaced flange 490. The displaced flange provides a surface or supportto retain the inner rotational element in the assembly by interactionwith the top bushing 450. The top bushing 450 may include a notch,channel, or other receiving structure to accept and interact with thedisplaced flange 490. In some embodiments the displaced flange 490 maybe a surface or shelf created by a reduction in the wall thickness ofthe inner rotational element 436. Such an assembly may be used in manyembodiments where a plurality of limiter activators are used as thestacked limiter activators may be assembled onto the other components ofthe rotation limiter as a single unit.

In some embodiments, the top busing 450 incudes a channel 451 to pressfit onto the outer rotational element 439. The top bushing includes anotch, channel, shelf, edge, or other structure on a radially outwardlyfacing surface to interact with and capture a complementary feature onthe limiter activator, such as first limiter activator 441. The featuresworking in concert prevent the limiter activators 441 and 442 from beingremoved past the top bushing 450 and thereby retained on the assembly.

Similarly, in some embodiments, the assembly includes an intermediatebushing 455. The intermediate bushing 455 includes a notch, channel,shelf, edge, or other structure on an outwardly facing surface tointeract with and capture a complementary feature, such as an edge orcorner on the limiter activator, such as first limiter activator 441 orsecond limiter activator 442 if two limiter activators are used, or thebottom most limiter activator if more than two are used. Theintermediate bushing 455 is preferably made of a material that allowsthe limiter activator with which it interacts to move freely andsmoothly. In some embodiments, the intermediate bushing may be excludedand the bottom most limiter activator may interact with and slideagainst a surface or surfaces of the outer rotational element 439.

As shown in FIG. 37 , in some embodiments a pin 437 may be omitted sothat a location exists where the protrusion 443 on the limiter activator441 does not engage with a pin 437. Such a location may be considered afree rotation position 600 or accommodation. With such a locationavailable, when the protrusion 443 of a limiter activator is at the freerotation position 600, no pin 437 is pushed in, and no pin 437 interactswith or stops rotational movement of the inner rotational element 436,thus allowing 360 degree rotation of the inner rotational element 436with respect to the outer rotational element 439.

In some embodiments, the limiter activators 441 and 442 may includeprotrusions 447 on the outer surface. Such protrusions 447 serve asmarkers or visual indicators to indicate where the protrusion 443 on theinner surface is present. By giving an outward indication of where thepins are displaced, the protrusions 447 on the outer surface alsoindicate the range of allowable rotation, or where the rotation willstop. In other embodiments, the outer surface protrusion 447 may act asa grip or area of leverage to allow the user to move or rotate thelimiter activator 441 or 442. In other embodiments, the position of theprotrusion 443 on the inner surface may be indicated by a mark, symbol,line, or other visual or tactile indicator. The outer surfaceprotrusions 447 may extend radially from the circumference of thelimiter activator 441 or 442. The outer surface protrusion 447 mayinclude transitional surfaces 447 a and 447 b that extend from thenominal outer surface of the limiter activator 441 or 442 to an area ofmaximum radial distance from the nominal outer surface. The transitionalsurfaces are preferably concave to provide better surfaces formanipulation by the fingers of a user of the device.

In some embodiments, the top or bottom bushings, or any surface that thelimiter activators bear upon, may include indexing marks 866 on thebearing surface. The indexing marks may be bumps, protrusions, orgrooves or divots. The corresponding surface of the limiter activator441 may include a protrusion, bump, groove 867, divot, or otherstructure to slightly interfere with the indexing mark. The groove 867may be located radially outward from the protrusion 447. Such indexingarrangement provides a click or other sound or tactile indication as thelimiter activator is rotated an indexed amount about the bushing. Thisprovides a user information as to the setting of the rotation limits ofthe assembly to known angles, such as 45 degrees.

As shown in FIG. 39-41 , the bushing includes a plurality of bumps orprotrusions about the outer circumference. The outer circumferencehaving the indexing marks 866, bumps or protrusions may be recessed fromthe most outer circumferential surface. The limiter activator 441includes at least one groove 867, indent or indexing mark on the innercircumferential surface, such that the indent will interfere with thebumps on the bushing 450 when the limiter activator in assembledrelationship with the bushing and rotated a sufficient amount to bring abump in contact with the indent. One skilled in the art will recognizethat the bump and corresponding indexing marks may be present on anyopposing surfaces of the bushing and limiter activator that bear againsteach other.

In some embodiments, the volume between the limiter activators 441 and442 and the outer rotational element 439 may include lubrication. Suchlubrication may include damping grease or other substances to providedamping and provide improved rotational feel.

The illustration of these particular embodiments should not be taken asrestrictive in any way since a myriad of configurations and methodsusing the underlying invention can be realized from what has beendisclosed in this application. One skilled in the art will recognizethat features of components may be placed on other components withoutdetracting from the invention disclosed. The foregoing disclosure ofspecific embodiments is intended to be illustrative of the broadconcepts comprehended by the invention.

What is claimed is:
 1. A monitor arm for supporting a monitor, themonitor arm including a base, an arm, and a rotation limiter, the armhaving a first end coupled to the rotation limiter, and the base coupledto the rotation limiter, the rotation limiter including an innerrotational element and an outer rotational element, the inner rotationalelement connected to one of the base or arm, the outer rotationalelement connected to the other of the base or arm, the inner rotationalelement located at least partially within the outer rotational element,the inner rotational element having a rib that rotates with the innerrotational element, the rotation limiter further including a pluralityof limit tabs, the limit tabs being selectively engageable to restrictthe rotation travel of the limit rib.
 2. The monitor arm of claim 1, therotation limiter further including a plurality of limit tab guides inthe outer rotational element, the limit tabs selectively movable withinthe limit tab guides.
 3. The monitor arm of claim 2 further including atleast one limiter activator to selectively activate or deactivate thelimit tabs.
 4. The monitor arm of claim 3, wherein the limiter activatoris a ring positioned about at least a portion of the outer rotationalelement, the ring including a protrusion to selectively move limit tabsas the ring is rotated.
 5. The monitor arm of claim 4, further includinga second ring positioned about at least a portion of the outerrotational element, the ring including a second ring protrusion toselectively move limit tabs at the second ring is rotated.
 6. Themonitor arm of claim 5, wherein the inner rotational element, the outerrotational element, and the ring are coaxially aligned.
 7. The monitorarm of claim 6, wherein the limit tabs are cylindrical pins having amajor axis parallel to the coaxial alignment.
 8. The monitor arm ofclaim 7, wherein the limit tab guides are apertures in the outerrotational element, the apertures sized smaller than the diameter of thecylindrical pins.
 9. The monitor arm of claim of claim 2, wherein thenumber of limit tabs is at least one less than the number of limit tabguides.
 10. The monitor arm of claim 9 wherein the base is a second arm.11. The monitor arm of claim 1 further including a connection platecoupled to a second end of the arm, the connection plate being insliding engagement with a first slide track, the connection plate havingperimeter edges, the first slide track including perimeter channels, theperimeter channels engaging the perimeter edges to retain the firstslide track in sliding engagement with the connection plate, a secondslide track, the second slide track including perimeter channels. 12.The monitor arm of claim 11, the second slide track perimeter channelsengaging the first slide track perimeter channels in a slidingengagement.
 13. The monitor arm of claim 11, wherein the second slidetrack perimeter channels engage the exterior of the first slide trackperimeter channels.
 14. The monitor arm of claim 11, further including amechanism to selectively prevent sliding movement of the first slidetrack relative to the connection plate, the mechanism including a brakeextending from an aperture in a face of the connection plate, a springto bias the brake in contact with a face of the first slide track, andan actuator to move the brake.
 15. The monitor arm of claim 14, whereinthe first slide track and the second slide track are back to back, thesecond slide track engaged in a sliding engagement with a secondconnection plate.
 16. The monitor arm of claim 11, further including asecond arm, the second arm connected to a second connection plate, athird slide track in sliding engagement with the second connectionplate, the third slide track and the first slide track joined with aconnector to interconnect the first and third slide tracks.
 17. Themonitor arm of claim 8, the rotation limiter further including a topbushing fit onto the outer rotational element and a bottom bushing, thetop bushing and bottom bushing capturing the first and second ringsabout the outer rotational element, the bottom bushing including atleast one key, the key extending from the bottom bushing into anaperture of the outer rotational element, the key preventing rotation ofthe bottom bushing about the outer rotational element.
 18. The monitorarm of claim 17, the top busing including a plurality of inner surfaceprotrusions extending towards the first ring, the first ring having asurface in contact with the plurality of protrusions, the first ringsurface including indexing structures to interact with the inner surfaceprotrusions.
 19. The monitor arm of claim 1, wherein the rotationlimiter is removably coupled to the base.
 20. The monitor arm of claim1, wherein the rotation limiter provides a visual indication of theallowed range of rotation set within the limiter.